Washington (AFP)
Rats, like humans, can help each other and feed those in need. But how do they make sure that their neighbor is really hungry? Thanks to odors, answers a study.
The main author of this study published Tuesday in the scientific journal PLOS Biology, Karin Schneeberger, told AFP that it is interested in how social animals can unmask "cheaters" among their fellows.
Studies have previously shown that rats share their food. But the researcher from the University of Potdsam (Germany) believed that the gestures and squeaks of rodents did not always reflect their true appetite.
In order to test this hypothesis, she and her team separated brown rats (Rattus norvegicus) into two groups - one having been deprived of food, the other well nourished - apart from a third group whose researchers wanted to test "generosity".
The air from the chambers in which the well or malnourished rats were found was introduced in turn into that housing the test population.
As a result, rats in the third group were much more quick to help their counterparts when air came from the well of malnourished rats.
The researchers then analyzed the air in the two chambers and identified very different organic compounds in each.
The fruit, according to them, of food more or less recently swallowed, of the process of digestion or even of a pheromone betraying the appetite.
This "smell of hunger", dixit Karin Schneeberger, could be used by rats, in addition to distinguishing profiteers, to reduce the suffering of their comrades.
"I don't really want to talk about empathy, because it would be very anthropomorphic, but having someone in distress near you can also cause you stress," she says.
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